I need a Asylum Doc about Diabetes

I have a couple of questions, and tell me my Doctor could be wrong. I went in with a sinus infection today, and he came up with it and a possibility of Diabetes.

Off of the symtoms which have been going on for the last couple of months(frequent trips to the bathroom, constantly thirsty, and being tired frequently). He tested me for Diabetes. Should I be that worried about this or could it all be nothing?